Sustainable Solutions for Contaminant Management in Produced Water

Abstract This paper aims to address the challenges and opportunities in managing produced water and its contaminants in the petroleum industry. The primary objectives include identifying key challenges in managing produced water, assessing current produced water treatment practices, identifying areas for improvement and establishing a new paradigm focusing on innovative sustainable solutions that benefit both the industry and the environment. In the featured case studies section of this paper, we will include detailed application case studies from Colombia and India. In these case studies, we will analyze the treatment and management of produced water and its contaminants using innovative and sustainable water treatment solutions and environmentally friendly methodologies. In the Colombia application case study, based on this oil/gas client’s analysis, the client required removal of several contaminants in the water stream to meet the regulatory irrigation standard. This particular wastewater stream contained elevated levels of manganese, iron, hardness, nitrate, color, sulfate, turbidity, TDS and trace emulsified hydrocarbons. We used bench testing to develop this secondary treatment process methodology (post oil/water separation) which was subsequently utilized in pilot and full-scale implementation. This process includes the utilization of an advanced oxidation process followed by three sets of backwash systems with specific treatment medias using a continuous batch process followed by tertiary treatment utilizing a reverse osmosis process optimized for seawater based on Total Dissolved Solids (TDS) with antiscalant injection and pre cartridge filtration. In the India application case study, the client’s treatment objectives were different as they only required treated water for re-injection. This wastewater stream contained total dissolved solids, total hardness, nickel, manganese, iron, bicarbonate, turbidity, sulfate and emulsified hydrocarbon. In this case, we also used bench testing to develop this secondary treatment process methodology (post oil/water separation) which was subsequently utilized in commercial scale implementation. A continuous batch process was also used in this application. This process included pH neutralization, and a continuous batch electrocoagulation process which included a post centrifugal filtration and clarification system. Upon completion of the continuous batch process, the water was filtered with back washing filtration systems with coated zeolite media and coconut activated carbon. These treatment medias were designed to further reduce the contaminants in the stream including turbidity and iron and small concentration of oil/grease remaining in the water. Following this process, an innovative liquid advanced oxidation treatment process (AOP) solution utilizing modified fenton reagent chemistry was initiated. This treatment process generated reactive oxygen molecules as well as hydroxyl radical compounds to further reduce any remaining organic and microbiological contaminants. The paper presents an analysis of the process treatment results and environmental implications of both the Colombian and Indian application case studies using the two different innovative treatment methodologies briefly discussed above. Lastly, we will propose sustainable solutions that benefit both oil/gas production companies and the environment contributing to a more sustainable petroleum industry.